Amphiphilic Pickering Emulsifiers Based on Mushroom-Type Janus Particles

Iron-based mushroom-type Janus particles consisting of a poly(sytrene-co-divinylbenzene) and a silica moiety both with controllable morphologies were successfully synthesized on the gram scale and investigated as surfactants for Pickering emulsions. Two oil–water model systems, namely toluene–water and vegetable oil–water, were stabilized, giving mainly water-in-oil (w/o) emulsions. By varying several parameters, including Janus particle morphologies and the oil–water ratio, fine-tuning of the emulsion systems was possible; it was even possible to invert the continuous phase to an oil-in-water (o/w) system. Furthermore, the emulsions were stable against coalescence and sedimentation and could be easily separated by centrifugation or a strong magnet. The synthesized mushroom-type Janus particles are suitable for creating Pickering emulsions and can be used as building blocks for creating nanostructures with tailored properties for specific applications